1. Field of the Invention
This invention relates to computer and/or telecommunications networks. In particular, the invention relates to voice signaling.
2. Description of Related Art
Support of voice supplementary services in enterprise Voice Over Internet Protocol (VoIP) networks requires that call servers that provide call processing interact with each other via exchange of signaling messages. This allows services to be supported across a community of call servers rather than only within a single server.
Current VoIP systems have very limited service capabilities and services are limited to basic call on any calls that cross multiple call servers. One approach is to add supplementary services signaling directly to the Session Initiation Protocol (SIP). However, this approach requires significant protocol development, which may require an extended development time. Another approach is to add Integrated Service Digital Network User Part (ISUP) signaling encapsulation in SIP. However, this approach only addresses carrier voice services and does not address enterprise voice services because ISUP is not significantly used within enterprise networks.
Therefore, there is a need to have a technique that provides fast implementation of services and does not require significant development efforts.
The present invention is a method and system to provide voice over a network. The system includes transmitting and receiving sides. On the transmitting side, a service message is created for a supplementary service using a signaling protocol over a network. The service message is encapsulated in a session message according to a session initiation protocol using a mail format. The mail format has a content type. The session message with the encapsulated service message is transmitted over the network. On the receiving side, a session message is received having a service message over a network. The service message is created for a supplementary service using a signaling protocol. The service message is encapsulated in the session message according to a session initiation protocol using a mail format. The mail format has a content type corresponding to the signaling protocol. The session message is parsed to retrieve the service message. The retrieved service message is processed to control the supplementary service.
According to one embodiment of the present invention, the content type is defined to correspond to the signaling protocol. The network is an Internet Protocol. The signaling protocol is one of a standard signaling protocol (e.g., QSIG) and a proprietary signaling protocol. The supplementary service is a voice over the network. The mail format is a multipurpose internet mail extensions (MIME) format.
The advantages of the invention include: (1) widespread utility because services are supported across a community of call servers, (2) ease of implementation because the technique uses existing service logic that has been already developed for narrow-band voice networks, (3) flexibility to mix multiple call servers, potentially from different vendors.
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.